passed <control>.DeviceContext. If an event, for example a resize, that
causes <control>.DeviceContext to be recreated, is initiated by the
drawing function, the Graphics object passed to it will no longer be valid.
+ Remember that resizing a control results in recreating <control>.DeviceContext
+ and this in turn results in destroying the old <control>.DeviceContext.
* If you're implementing a theme and you need to know about certain states
of the control, you have to access the internal variables of the control